下列表述哪一个是正确的?（）。

A.利率是指资金在单位时间内产生的利息

B.保险人经营人寿保险的营业费用应包括在纯保险费内

C.一笔资金在一定期间后所得的本利和称为现值

D.不仅本金生息而且利息也生息，这是单利计息法

句型转换。

1. Mary was able to find the way back home. (改为否定句)

    Mary _______  _______ to find the way back home.

2. I don't know what I should do. (改为同义句)

    I don't know what _______  ________.

3. It took them ten days to finish the work. (对画线部分提问)

    _______  ________ did it take them to finish the work?

4. I'd like to buy some tickets to the wonderful concert. (改为一般疑问句) 

                  you like to buy                tickets to the wonderful concert?

5. The book is too expensive for me to buy. (改为同义句)

    The book is               expensive               I can't buy it.